Did you know that fall is the best time to overseed your lawn? This is considered “dormant seeding”, which means you won’t see any new growth this year. However, when the soil is warming up in the spring the seeds will start to germinate. This gives you the maximum length of growing period before weeds start to compete with the new grass. It also allows the seed to get moisture from the melting snow, since sprinkler systems aren’t turned on until later in the season. For dormant seeding, we recommend planting in October- any earlier, and the seeds may start to germinate before the snow starts, leaving the young grass susceptible to drought. While overseeding is a fairly easy process to do yourself, it can be confusing trying to determine which type of grass seed to buy. There are many different varieties out there!

Warm vs Cool Season Grasses
Lawn grasses come in two main categories- warm season and cool season. As you may have guessed, cool-season grasses are used in Montana and other northern parts of the country. They are named as such because they do most of their growing in the spring and the fall, when the weather is cool. This is why fertilizing in the spring and fall is so strongly recommended- it gives your lawn nutrients when it is using them the most. Cool season grasses are able to survive cold winter temps, while warm season grasses cannot. The latter is only used in the southern-most areas of the country. 

Types of Cool Season Grasses 

Kentucky Bluegrass
Kentucky Bluegrass is the most common type of grass used for lawns in our area. Unlike the name suggests, this grass is native to Europe and Asia- not Kentucky! There are a few reasons it has become such a common choice for lawns.

Appearance
It has a deep emerald green color. The blades are narrow and boat-shaped. You can typically see a distinct vein running down the middle of the blade. This grass is soft to the touch. 

Pros

• Grows thick and dense, creating a desirable look and feel for lawns. The narrow blades give it a soft texture which is great for bare feet and yard activities. 
• Spreads through its underground roots, which makes it easier for it to repair itself when damaged.
• Holds up to high foot traffic. 
• Thrives in full sun, so it is great for lawns that do not have a lot of shade.
• Very cold-hardy; can withstand the harshest temps winter throws at it. 

Cons

• It has a shallow root system, which makes it more susceptible to drought stress in the heat. Proper watering is very important to keep this grass looking green and lush in the summer months!  
• Is sensitive to soil quality and compaction. Our fertilizer programs are a great option to ensure this grass stays healthy. 

Tall Fescue
Tall Fescue is another very popular choice for lawns. While the texture is less ideal for lawns than bluegrass, it generally requires less maintenance. 

Appearance
It is a dark to medium green color. (More of a ‘classic’ green tone than bluegrass.) The blades are wide and stiff, giving it a coarse texture. 

Pros

• Tolerates both sun and shade. 
• Has a deeper root system than other grasses, so is more tolerant to drought during the hot summer months.
• Is less sensitive than bluegrass to soil type and compaction, so may still thrive with less frequent fertilizer. 

Cons

• It has a “bunch type” growth pattern, which means it spreads by growing above ground. Because of this, it does not easily repair itself when damaged. It may need overseeding each year in high traffic areas
• It has a coarser texture than other grasses, giving the lawn a less ‘soft’ feeling under foot. 

Fine Fescue
Fine Fescue is similar to Tall Fescue, with a few notable differences. It has a softer feel, but is even more susceptible to damage from foot traffic. 

Appearance
It is a dark to medium green color. The leaves are very narrow and fine, giving it a soft texture. 

Pros

• Tolerates both sun and shade. 
• Is tolerant of poor soil conditions and high elevations. 

Cons

• Does not hold up well under frequent foot traffic. 
• Is susceptible to some diseases and grubs. 

Perennial Ryegrass
This grass is commonly found in grass seed mixes. It germinates quickly, which can provide shade for the slower-growing grasses in the mix. It is also commonly used for pasture grass and erosion control areas. However, we do not recommend using it for a full lawn as it will likely not survive the cold winters we get here. 

Appearance

It has a rich green color, which is similar to Kentucky Bluegrass. It has narrow, blade-shaped leaves. The blades are shiny on the underside, which is one way you can tell it apart from Bluegrass. 

Pros

• Germinates and grows very quickly. 

Cons

• It has a “bunch type” growth pattern, which means it spreads by growing above ground. Because of this, it does not easily repair itself when damaged. 
• Tends to have a more patchy appearance than other grasses.
• Does not tolerate extremely cold temperatures. 

Conclusion
Grass seed mixes are a common option you will see available in stores. The mixes allow folks to take advantage of the benefits from multiple different grasses, mitigating some of their downsides. Depending on your preferences and lawn type, you may want to look for a mix that is dominant in one grass or another. We recommend purchasing from local stores, as they typically have higher quality products, as well as products specific to our climate. Always be sure you are purchasing cool-season grasses. 

When laying down new seed, be sure that the soil is nice and loose; it is difficult for seed to germinate in compacted soil. If your soil is pretty beat down, we recommend putting down a thin layer of topsoil or mulch before spreading the seed. When Yard Guard treats lawns, we avoid spraying weed control on the new seedlings, as herbicides can hinder growth when it is young. Overseeding in the fall will give the new seeds the entire spring season to germinate and grow- leaving you with a nice full lawn by the time summer arrives. Happy planting!